My invention, ROD HANDLING APPARATUS, applies to the processing of tubes, especially the heat treating of nuclear fuel rods, hereinafter called rods, which are used in the core of nuclear reactors. While these are actually thin walled tubes, they are called rods in the nuclear industry.
The rods are sealed on one end, then heat treated at that end. This is in addition to processing such as welding, deburring, cleaning, pressure testing, etc. After heat treating, nuclear fuel pellets are inserted into the rods and the other end is sealed. The filled rods are then grouped into bundles and placed inside the core of a nuclear reactor where water is circulated, heated by the rods and used to generate electricity.
Until now, walking beam devices were one of the main machines used to transport the rods for processing. The problem is that walking beams must move in a rectangular or square transfer path. The rod must first be lifted, then transferred forward, lowered and placed in a support. Then the walking beam must travel below the rods in the supports in order to return to pick up another rod and transfer all of the rods one step at a time.
My invention processes multiple rods which may be up to thirty or forty rods at a time. The accompanying drawings shows twelve rods being processed for clarity and brevity. Transferring these with a walking beam requires thirty or forty individual lifts, transfers and lowerings making this inefficient, time consuming and costly.
In addition, a walking beam complicates the design of the machine and causes handling problems with possible rod jams, loss of control, or increased machine maintenance. Another problem is that after the heat treating operation is complete and the rods are on the walking beam supports again, the rods must be removed from the machine. This means that the walking beam would have to make a cyclic motion to remove each rod from the system meaning another thirty to forty motions. Another drawback is that a walking beam is not suited for ease of changeover for different diameters of rods.
Other machines are based on pneumatic devices, endless conveyor belts, rotary motion with cams, or shafts, and hydraulic units but cannot meet all the benefits of my invention.
My invention is a modified walking beam which can continually and automatically process multiple rods and which can accommodate rods of varying lengths and diameters and is precisely controlled using computer and servomechanism technology resulting in high efficiency and the ability to be operated by unskilled labor. Since the rods must be kept straight, my invention consists of numerous supports to guard against flexing and bending. My machine answers the need for one which will result in economies of time and labor, needing little maintenance, yielding a superior product and which has a ready market.
This machine can also be used to perform many physical and chemical operations on rods, tubes, bars, pipes, etc., on either one or both ends.